Search Documents

By Y Yang

This paper discusses various issues surrounding the metallurgical control for furnaces, especially focusing on processes with long time-constants and æmetallurgical memoriesÆ. Examples will focus on furnaces accepting particulate and sometimes ill-defined feeds, eg submerged-arc furnaces, blast furnaces, secondary scrap smelting operations, recycling operations, waste incinerators, etc. Generally, because of the usually higher metallurgical time constant of these furnaces, these reactors have to be controlled in a feed-forward manner by the use of a hybrid of æblack boxÆ or empirical and ægrey boxÆ semi-empirical first principles metallurgical modelling and simulation techniques in a supervisory metallurgical control capacity.

Jan 1, 2000

Roles of Mineral Impurities and Sulfur in the Leaching Behaviour of Pre-Reduced Ilmenite Ores

Sep 13, 2010

Mineragraphy is a coined term to signify the field of microscopic investigation of ore minerals. The term is not euphonius and is sometimes regarded as superfluous because the subject is no more than an enlargement of the scope of petrology. In the past the practical field of petrology has been largely limited by the instruments which were designed for the study of rocks and' the microscopical properties of the transparent minerals. The addition of mineragraphy has been brought about by the use of the reflecting microscope and a totally different technique.The use of the petrological microscope, as it has been employed in the training oi geologists and mining engineers for nearly half a century, has been justified many times, not only in its application to general geological problems, but also in the more restricted field of the exploration and examination of ore deposits. It provides information of the gangue minerals and rocks associated with an ore body which is of great value in some mining fields. In cases where ore deposits occur selectively in certain favourable types of rock, the recognition and delineation of these rock types is a useful guide in prospecting. The Boulder Belt at Kalgoorlie forms one of the most striking examples in Australia where important significance is attached to different rock types, and the petrological microscope is essential to their elucidation.

Jan 1, 1932

In the course of the last twenty eight years the copper lodes of New Caledonia have been periodically worked or abandoned, until quite recently, probably attracted by the higher price of the metal, British capital has again been induced to embark upon the further development of several copper properties, which at present give reasonable promise of becoming regular producers. Owing to its proximity to Australia (only a three day's journey by mail steamer from Sydney) New Caledonia becomes of additional interest to Australian commerce in general, and it is to be hoped that the French Government may see their way before long to make the best of this natural position, to the mutual benefit of both countries concerned.Op till now all copper ores and concentrates which have been shipped from New Caledonia, were treated in Australian smelting works furthermore, Australian mine managers and miners have from time to time been connected with New Caledonian mining ventures, but, unfortunately, it must be said that nearly everyone of them returned to Australia thoroughly disgusted with his experience over there. Even to the casual observer, it is not so very difficult to find a proper explanation for these shortcomings in the peculiar economic conditions of the 'French colony, as many of the objections which have hitherto existed in connection with mining operations, were the direct consequences of a system of colonisation which could not possibly have been productive of better results.

Jan 1, 1901

The rocks of Waihi and the surrounding district are almost entirely rhyolitic and ande5itic in character. Sedimentary rocks, with the exception of some surface deposits of clay loosely compacted conglomerate, etc., and one or two thin and broken beds of a very poor lignite, occasionally changed by igneous agencies into a bituminous coal, are almost absent. In the shafts sunk by the Waihi and Grand Junction companies outside the outcropping andesitic area of the Martha Hill, more than one old surface or lake bottom has been passed through. At these points layers of sand, consolidated volcanic mud and tuff, accompanied by numerous broken fragments of imperfectly silicified wood have been enccuntered, but these occurrences may, for the purpose of this paper, be neglected.The youngest rock of the district are rhyolites, probably of Pliocene age. At least three distinct classes of rhyolitic lava, each possessing features of unusual interest, may be made out. None of these, however, is gold-bearing. The youngest flow, a light-coloured, fine-grained rock, is remarkable owing to its enclosing at times fragments of carbonised wood, varying in size from mere specks up to quite large pieces of almost pure charcoal. Rhyolitic tuff is also met with. The rhyolites cover a large extent of nearly flat country east, south, and west of Waibi, here and there rising into barren, stony hills.Below the rhyolites, geologically speaking, but for the most part. forming hills which bound the rhyolitic plain, or rise out of it as isolated patches, come ahdesites of older...

Jan 1, 1902

The El Pe±on gold-silver deposit comprises four epithermal, low-sulfidation veins, which contain 2.9 million oz Au and 48 million oz Ag. Provisional data on alteration mineralogy, fluid inclusions, and vein textures constrain the chemistry and hydrology of the hydrothermal system responsible for ore mineralisation at El Pe±on. Alteration minerals include quartz, adularia, albite, illite, smectite, calcite, chlorite, and pyrite. Alteration minerals suggest the existence of near neutral pH, low salinity hydrothermal fluids, which circulated over an area greater than 18 km2. Complex mineral zonation patterns result from variations in host rock permeability and composition, overprinting alteration possibly produced by thermal waters from surficial and peripheral parts of the hydrothermal system, and supergene weathering in the hyperarid environment. Upflow zones were focused along N-S and NE trending structures, producing crustiform quartz-adularia+carbonate veins. Fluid inclusion data indicate vein deposition from low salinity (

Jan 1, 2002

By Taylor G. H

The Triassic Ipswich (SE. Queensland) coals are of bituminous rank. The more exact rank of individual samples was determined by measuring the reflectance of the vitrinite. While in general the rank of the coals increases with stratigraphic depth, minor reversals, probably related to igneous intrusions, occur.The Ipswich coals form a coherent group so far as petrographic type is concerned. All are comparatively rich in vitrite and clarite, cutinite being the common maceral of the exinite group. The mineral contents of all the coals are comparatively high, clay and quartz being most abundant. The coals appear to be of essentially autochthonous origin, and to have been formed under conditions of fairly rapid subsidence.While the use of the coals is at present restricted to combustion, most have pronounced coking properties, as would be predicted from their petrographic composition and reflectance. However, the high mineral content of the coals would be a limiting factor in their use for coke-making.INTRODUCTIONDuring the last ten years, the Division of Coal Research, Commonwealth Scientific and Industrial Research Organization has carried out an extensive investigation of Australian coals, providing a wide range of analyses of most of the important of them. Special attention has been given in recent years to Queensland coals.Most seams were sampled as a number of subsections, enabling the internal variations, as well as the overall properties, to be assessed. The lenticularity of many of the mineralrich layers may tend to limit the significance of the samples, particularly in respect of ash yield, but although the vertical distribution of mineral matter may vary considerably from one sampling position to another, the lateral variation of the total mineral matter in the whole seam may not be great.Apart from extensive chemical analyses and utilization...

Jan 1, 1963

This paper presents the near-field rock damage owing to production blasting in limestone quarry in the western region of Japan. The study's purpose is to learn the mechanism of crack development due to blast vibration. In this study, blast vibration's magnitude was expressed with peak particle velocity (PPV) which was obtained based on seismographs recorded database. In attempt to pursue a research's purpose of this study, there were two considerable interests: near-field blast vibration propagation and prediction, and crack observed and prediction. Furthermore, with regards to considerable interest of the study, there were three essential aspects which were challenged, such as: monitoring and interpretation of seismic wave propagation in a rock mass near large explosive charge of production blast scale, measurement of blast rock damage in adjacent to blasthole, and determine critical value of PPV which may produce significant rock damage. In order to determine precision critical PPV, understanding correlation between rock damage with vibration level is firstly important to be done. This paper also discusses how to measure, detect and quantify near-field blast vibration and blast rock damage in adjacent to blasthole.

Dec 6, 2010

The ready solubility of gold in dilute aqueous solutions of the cyanides of the alkalies or alkaline earths provides a convenient method for the separation of the precious metal -from the large surplus of associated materia1. The finely ground ore is pulped with a weak solution of cyanide, agitated to dissolve the gold, filtered and washed. The lowgrade filtrate is then clarified and the gold precipitated by some electronegative agent, the most usual being finely divided zinc or zinc dust. The slight precipitate is collectedon some form of filter coated with a filter aid, the filter cake being then known as "gold slime".A typical analysis of this slime is given in Table 1.

Jan 1, 1956

By P González, J Videla, E Córdova, I Gottreux

Currently, underground mining of deeper massive deposits with lower grades, harder rock conditions in high strength environments, entails difficulties in caving, fragmentation and seismicity of the orebody.So far, the use of preconditioning (PC) with hydraulic fracturing (HF) has shown positive results in terms of seismic response and caving performance, while PC combined with explosives aims to weaken the rock mass, causing an additional effect on fragmentation.In particular, mines commonly referred to as ‘supercaves’, operated by caving methods, have the need to integrate mine to plant processes, where rock fragmentation appears as a key tool. In fact, it implies making mining and comminution processes more efficient to the plant and for mines, it justifies the search of innovative solutions in drilling and blasting techniques to precondition the rock mass. The following paper aims to show the feasibility of numerical blast modelling to weaken the rock mass using explosives, mainly through sensitivity analysis applied to designs to minimise bias and uncertainty in the results. It is shown how the presence of structures, their geometry and in situ stresses influence or interfere with the PC method being used.From the work, it is concluded that better knowledge on the application of explosives weakening allows specialists to strengthen numerical models associated with every design and therefore previously validate their applicability, helping to understand complex phenomena such as the propagation of mechanical waves in non-elastic heterogeneous media. In this sense, it is understood that while there are studies (Sanchidrián, Segarra and López, 2006) showing that the transfer of energy in the rock mass could be even greater in a confined environment, the more competent rock mass and higher in situ stresses interfere mostly on the effectiveness of a technique using explosives.CITATION:Gottreux, I, Córdova, E, González, P and Videla, J, 2016. Preconditioning modelling and explosives effectiveness in block caving, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 683–688 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Failure of rock materials is a process of crack propagation. Crack initiation takes place when the crack tip stress intensity K reaches a critical value called fracture toughness, K1C. The rock fracture toughness is known to be affected by the surrounding environment such as temperature, confining pressure and humidity. In order to examine the effect of humidity, a series of semi-circular bend tests were performed under various water vapour pressures in a rock material that is known to be anisotropic. Water vapour promotes stress corrosion of rock and therefore the fracture toughness was found to have a decreasing trend with increasing water vapour pressure. The rate of decreasing the fracture toughness depends on the microcrack density that promotes the migration of water vapour into the rock. Also in an anisotropic rock, the fracture toughness depends on the direction of crack in relation to the anisotropy of the rock material.

Dec 6, 2010

By A N. Danoucaras, S E. Goater, D Hearne, A M. Bansuan

It is globally recognised that existing and emerging mining activities should be conducted in a æsustainableÆ manner for the entire life of mine. Many companies annually publish corporate sustainability reports to demonstrate their actions in accordance with international expectations. This concept of sustainable mining practices also applies to mine water management, with influences often extending beyond site operations, affecting surrounding catchments and community users. This paper explores differences in conceptual and operational terms of æsustainableÆ mine water management within the Philippines. Outcomes of a review of corporate sustainability reports, governance documentation, research programs, and stakeholder knowledge acquired through action-research workshops are presented. The paper aims to inform and support future capacity building exercises delivered by the International Mining for Development Centre (IM4DC), with outcomes tailored to government officials and policy makers of developing countries. The project is funded by IM4DC, which is working with AusAID to identify needs and develop capacity with regard to mining for development; specifically, issues pertaining to governance and regulation, social and environmental sustainability, and operational effectiveness in developing countries.CITATION:Bansuan, A M, Goater, S E, Danoucaras, A N and Hearne, D, 2012. Integrated sustainable water management in mining for development in the Philippines, in Proceedings International Mine Management 2012, pp 205-226 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

Sufficient time has elapsed since the enactment of the amendments to the mining legislation in 1981 to enable an examination to be made of the way in which the licensing system operates in practice. One of the most important decisions in resource management in New Zealand is whether or not rights of access to the resource should be conferred by the Crown upon an appropriate private sector participant. The licensing system is the means for allocating these rights of access. The manner in which the licensing system is administered, therefore, is crucial to natural resource management in New Zealand. What is the mining licensing system in New Zealand designed to achieve? This simple question admits of no easy answer. Is it the identification and development of the mineral resources of New Zealand? Are these objectives tempered by issues of resource conservation and environmental protection? Is a balance to be achieved among these competing factors? Does the legislation contain any priorities? Does the system respond in an ad hoc manner to particular facts and circumstances or does it operate within a more predictable framework? To what extent are decisions made on access to minerals with reference to the development or conservation of other resources? These questions may be summarised in the title to this paper which poses the question whether mining licences are instruments for resource management.

Jan 1, 1988

By P K. Banerjee, S Kumar

Indian iron ores with less than 62 per cent Fe are currently unexploited, except for a few sectors which export them to foreign countries. It is anticipated that by 2012 the countryÆs domestic steel production is likely to rise to the tune of 60 million tonnes per annum. To meet this requirement, it is necessary to utilise not only the existing high-grade deposits but it is also necessary to look into exploiting the leftover iron ores of lower grades. Hence, reserves with Fe content 62 per cent and below (particularly the ores with In the present paper, an attempt has been made to beneficiate three different types of low-grade iron ores selected from three different parts (states) of the country. In the paper, alternative routes for beneficiation and effective utilisation have been tested using different techniques in the laboratory in an attempt to match their (Al2O3/SiO2) ratio after thorough characterisation and liberation studies. The paper also encompasses the geological formations, occurrences and distribution of Indian iron ores as well as highlighting the problems associated with the fines, possible metallurgical routes, and their market segregation from the perspective of end users.

Jan 1, 2007

By M E. Barley, A D. George, M Kneeshaw

Detailed pit and outcrop mapping of sedimentary rocks and their alteration is providing insights into fluvial processes that operated during deposition of the world-class Yandi channel iron deposit. Five prominent rock units are traceable along the strike of the Yandi deposit and permit correlation of open pits and mesas. These units are the Eastern Clay Horizon (ECH), granule-pebble conglomerate (GPC), Main Ore Zone (MOZ), Basal Denatured Zone (BDZ), and Basal Conglomerate (BCONG). The upper part of the deposit is characterised by a transition from spheroidal grains with well-defined rims and nuclei to larger, subangular grains with poorly developed rims. The distribution of rock types and sedimentary features such as lateral accretion surfaces, channel scours and fills, graded bedding, cross-bedding, reworked horizons, and slumped strata are common at Yandi and indicate deposition in a fluvial system. Bedding is well preserved despite modification of original grain shapes and textures and introduction of secondary silica and alumina in the upper part of the deposit. The high lithic and clay content of the GPC and ECH possibly reflect changes in source area or a hiatus in deposition of the Marillana Pisolite. The MOZ and the BDZ may be the same depositional unit with the latter recording alteration by groundwater and destruction of primary textures and other sedimentary features. The BCONG is a channel lag deposit reworked during deposition of the MOZ. This interpretation is supported by the dominance of basement-derived lithic clasts, the presence of BCONG clasts, the variable thickness of the unit along strike and the presence of BCONG clasts in the BDZ.

Jan 1, 2002

By C Thompson, D Connelly

The history of mill liners has evolved over time and this paper tracks the changes and development of liner technology. It provides an overview of the primary types of liners, the design and the materials of construction. The design of a mill liner is driven by application, materials of construction, casting technology and handling issues. The choice of solid steel, grid liners, rubber or composites and magnetic liners is based on many factors.The methods used for monitoring wear and predicting eventual change out time are many and varied. The contribution of discrete element modeling (DEM) analysis in predicting wear profile is discussed.Mill trajectory and DEM software programs are used with great effect to predict the effect of lifter height, face angle, high low lifters or mill speed. In the field, trial and operational experience is used or improvements/design concepts at one operation are applied to another. Broken mill lifters, accentuated wear and other problems can be better understood using hardness testing, chemical analysis and photo micrograph analysis of pearlitic or martensitic structure along with fracture face observations. This forms a part of the typical root cause analysis. However given correct and sound liner and lifter, feed and discharge design media selection, and materials of construction, the majority of premature liner or bolting failure is normally attributed to incorrect operational methods such as excessive high ball to feed ratio, incorrect mill speed relating to lifter ball throw, incorrect media selection, "tramp" material entering the mill charge from upstream or recirculating process and understanding the specific mill operation in question.It is hoped that this paper will benefit mill operators who are faced with challenges of improving wear life and at the same time optimizing mill throughput and performance.CITATION:Connelly, D and Thompson, C, 2013. The selection design and application of mill liners for large wet grinding mills, in Proceedings MetPlant 2013 , pp 133-140 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By Monger N. R

Factors leading to the decision to use Joy Continuous Miners for pillar extraction in the Burwood Colliery are outlined. A detailed description is given of the Joy 1-CM-2 Continuous Miner, including the power supply to the machine, and the method of cutting coalfrom a face. Modifications found necessary in practice are dealt with.The Joy 10 S.C. shuttle car used in conjunction with the Miner, and alterations made to this unit, are then described, together with Ancillary units for the whole installation such as transformers, motor generator set, air compressor,_ cables for power supply and water supply for dust suppression.Special arrangements were necessary to transport the Miner and Shuttle Cars through the tunnel to the Victoria Tunnel seam, and the method of overcoming the transport difficulties is discussed. Manning of the Continuous Miner unit, and final preparation andsubsequent working of the pillars is outlined. Special attention must be given to maintenance of the machines.It is concluded that the combination of Joy Continuous Miner and Shuttle Car is an excellent method for removing pillars in the Burwood Colliery.INTRODUCTIONThis paper deals with the Burwood Colliery in the RH.P. Group in which some units are engaged in the mechanical extraction of pillars with Joy Continuous Miners.In 1941, an amendment to the Coal Mines Regulation Act of N.S.W. forbade the extraction of pillars by mechanical means unless with the express permission of the Minister for Mines. As this permission was not forthcoming, no mechanical extraction of pillars took place in Australia until 1954 As it was doubtful during most of this period whether mechanical extraction would ever come about, coal generally was won with a view to maximum extraction in the first workings, thus giving rise to centre gannon bord panels and 45° angle cut throughs as shown in Fig. 1.

Jan 1, 1957

Using Positron Emission Particle Tracking (PEPT) to Investigate Industrial Systems

Sep 13, 2010

R. C. BUCKETT (Lake View and Star Limited) : At the outset I should like to add my congratulations to those already extended to Mr..Norwood on his excellent paper, which has given us all an inspiration to strive further to improve our plant recoveries. In some respects this paper has left us so little to discuss without considerable time spent on. further research work. At all points one is met by a baffling array of facts which leave one feeling hesitant to speak.The careful and methodical way in which Mr. Norwood went along step by step until all channels of research presenting themselves were tested to his own satisfaction leaves me with but a few comments to make. Particularly striking to me is the explanation of the residual gold values in calcines by recrystallization of haematite and here is a line to be attacked by future studies. This will be mentioned again later.Particularizing on the paper, the first point that struck me was the method of change of pyrite through to the final haematite. I have never been able to satisfy myself that a sample taken from various positions along a roaster when cooled, as described on p. 397, represented a fair sample of the conditions at that point, but I must confess that I have not found a substitute that did satisfy me.However, the following figures are illuminating... But to fill dry a receptacle of known volume with calcines, as described by Mr. Norwood, gives the following apparentspecific gravities:

Jan 1, 1940

By Dippenaar R, Evans T

Twin-roll continuous casting technology is rapidly approaching commercialisation. Fundamentally different than conventional continuous casting, heat transfer and hence solidification during twin-roll casting are governed by the interfacial melt/mould thermal resistance, as opposed to the resistance of the solidifying shell. Under these conditions the interface resistance is predominantly controlled by the melt/substrate wetting behaviour. The very early stages of melt/mould contact are characterised by highly transient heat transfer conditions. The overall melt cooling rates prior to the formation of the first solid are reported to be in the range of 1000 - 50000 K/s with melt undercoolings of up to 300 K. At the points of intimate melt/mould contact the thermal resistance is approaching zero, where cooling rates and undercooling much larger than those reported in the literature are probably occurring. Improved wetting will reduce the energy barrier for nucleation while at the same time increasing the cooling rate of the liquid. Since the overall nucleation rate is controlled both by the rate of cluster formation and the rate of atom transfer to the nucleus, a critical cooling rate will exist above which the nucleation rate is expected to be reduced. Under these conditions, it is possible that the first solid phase to form is a metastable glass which subsequently transforms into a crystalline phase. The implications on nucleation and early growth are also discussed.

Jan 1, 1999